body {
  font-family: Arial, sans-serif;
  background-color: #f7f7f7;
  color: #333;
  margin: 0;
  padding: 0;
}

.container {
  max-width: 600px;
  margin: 50px auto;
  padding: 20px;
  background: #fff;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
  border-radius: 8px;
}

h1 {
  color: #2c3e50;
  text-align: center;
}

fieldset {
  border: 1px solid #ddd;
  padding: 15px;
  margin-bottom: 20px;
  border-radius: 5px;
}

legend {
  font-weight: bold;
  color: #34495e;
}

label {
  display: block;
  margin-bottom: 10px;
}

button {
  display: block;
  width: 100%;
  padding: 10px;
  background-color: #2ecc71;
  color: white;
  border: none;
  border-radius: 5px;
  font-size: 16px;
  cursor: pointer;
}

button:hover {
  background-color: #27ae60;
}

#result {
  margin-top: 20px;
  padding: 15px;
  background-color: #ecf0f1;
  border: 1px solid #bdc3c7;
  border-radius: 5px;
  text-align: center;
  font-size: 18px;
}